Conventionally, there are multi-function image processing apparatuses having a plurality of functions, such as a printer, a scanner, facsimile communication and the like, which are capable of connecting with a data processing terminal, such as a personal computer (PC). Each of the functions of the image processing apparatus can be controlled independently by the data processing terminal. However, to simultaneously operate these functions so as to fully take advantage of the plurality of functions, the following workload is necessary. First of all, in the data processing terminal, it is necessary to add header information, which specifies a function such as a printer, a scanner, facsimile communication or the like, to the head of an intended control command, edit and packet the data, and transmit the packeted data to the image processing apparatus. Therefore, there are large problems in terms of an alteration workload of a driver which is installed in the data processing terminal, complexity of the control, and a throughput.
Meanwhile, in the image processing apparatus which receives the packeted data from the data processing terminal, it is necessary to analyze the packeted data by a main controller of the image processing apparatus to specify whether the data is related to a printer, a scanner, or facsimile communication. In addition, it is necessary to delete and edit the header information, added to the head of the control command, before transferring the data to the corresponding function (e.g., printer, scanner, facsimile or the like).
Since command data from a data processing terminal is always analyzed by the main controller of the image processing apparatus as described above, there are large problems in terms of poor performance due to the analysis performed by the data processing terminal, and a program design for the analysis.
In view of this, an external interface and an internal interface are matched in units of logical channels so that command data from the data processing terminal can be transferred to respective functions of the image processing apparatus, e.g., a printer, a scanner, or the like, without being analyzed or changed by the main controller of the image processing apparatus.
As described above, since command data transmitted from the data processing terminal to the image processing apparatus can be transferred to respective functions without changing the command data to a unique form of the image processing apparatus, the time required for command analysis of the image processing apparatus can be reduced, and permeability of the command data from the data processing terminal increases. As a result, the performance of the entire image processing system improves.
Meanwhile, there is an image processing apparatus having an energy-saving mode. Herein, the energy-saving mode is a standby mode where an apparatus is on standby with small power consumption. In a case where a user operates an apparatus in the energy-saving mode, the apparatus returns from the energy-saving standby state and performs operation. For instance, according to an apparatus having a conventional energy-saving mode as disclosed in Japanese Patent Application Laid-Open No. 2000-78325, the apparatus shifts to the energy-saving mode when it is on standby, but comes out of the energy-saving mode when it starts operation, and returns to the energy-saving mode after the operation. Furthermore, according to an apparatus disclosed in Japanese Patent Application Laid-Open No. 2000-125057, in a case where a user directly operates the apparatus or the apparatus receives a command from a PC in the energy-saving mode, the command is analyzed by a main CPU of the apparatus and electric power is supplied only to the units to be used in accordance with the analyzed command.
However, in the above-described methods, power consumption of the respective functions, such as a printer, a scanner, or the like, of the image processing apparatus in the energy-saving mode is not always kept low. For instance, assuming a case where a printer has a feature for automatically turning on its power upon command reception, e.g., an automatic power resume feature, since the printer is on standby in a command-receptible state, the printer consumes electric power for this feature even if power supply is reduced.
Furthermore, in the case of an image processing apparatus where an external interface and an internal interface are matched in units of logical channels, only a command from a data processing terminal can be used in the image processing apparatus. Therefore, if each function of the image processing apparatus does not have the automatic power resume feature, in a case of a power-off state, the function whose power is turned off cannot receive the command. As a result, the function cannot turn on the power. However, if the automatic power resume feature is provided to each of the functions, power is consumed even in the energy-saving mode as described above.